Note: Descriptions are shown in the official language in which they were submitted.
` W O 93/05913 PC~r/US92/07819
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2109414
A
CHIP-BR~RTNG TOOLHOLDER WITH ADJUSTABLE ORIFICE CAP
FIELD OF THE lNv~NlION
The present invention relates generally to
machine toolholders for holding a cutting insert
adapted to engage a workpiece and remove a chip
therefrom, and more particularly to hydraulic chip-
breaking toolholders which use a high velocity fluid
stream to break the chip removed from the workpiece
into small segments.
B~CRGROUND OF THE lNv~NlION
Metal work cutting tools generally include a
disposable cutting insert and a toolholder adapted to
firmly hold the cutting insert. The cutting insert is
brought into contact with a metal workpiece while the
workpiece is rotated to remove a chip from the
workpiece. There is a tendency for removed chips to
form long, continuous strands rather than break into
small segments. These long strands spiral and cause
hot metal liberated from the workpiece to remain in
contact with the cutting insert for a longer duration
and often tangle up with the workpiece or the
toolholder. If the strand tangles up with the
workpiece or the toolholder, the operation must be
halted so that the strand may be manually broken. As
most metal working operations are intended to operate
nearly automatically, this is a very undesirable and ~
expensive task. Furthermore, the life of a cutting ~ -
insert, generally being formed from carbide steel or a
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similar metal, is heavily dependent upon operation
temperature. Under normal conditions, the cutting
insert is exposed to intense heat generated in cutting
chips from the workpiece. This heat is significantly
increased when hot metal chips remain in contact with
the cutting insert for an extended duration as they do
when the chips form continuous strands.
The need to break chips to avoid stranding is
well understood and recognized in the metal working
industry. A great deal of design and experimentation
has been devoted to the development of efficient and
effective means for breaking chips. For example, some
inserts are designed with integrally formed chip-
breakers. Such chip-breakers usually comprise an
obstruction in the path of the chip for deflecting and
curling the chip. By bending the chip to the limit of
its ductility, the chip breaks into small segments.
Another method of chip-breaking is to direct
a high velocity stream of coolant at the chip. The
stream bends the chip and cools it, making it more
brittle. This combination of effects causes the chips
to break off into smaller segments rather than form
long strands. The coolant also serves to cool the
cutting insert thereby extending its operational life.
Methods have been developed for directing a
high velocity fluid stream at the cutting insert which
use an external fluid line attached to the toolholder.
Often, several tools will be used to work on a single
workpiece, necessitating changing of the toolholders.
The additional steps of disconnecting and reconnecting
the external fluid line significantly decrease the
speed and efficiency of toolholder replacement.
A tool assembly disclosed in Patent No. ~,
4,955,264, has been developed which obviates the need
for an external fluid line. This tool assembly
includes a coolant passage formed in the toolholder and
a cap having a constricted outlet attached to the
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outlet of the passageway. Whlle this apparatus solves the
problem of conventional tool assemblles, lt has a signlflcant
llmitation. Often a slngle tool assembly may be used to make
several dlfferent cuts on a workplece. These dlfferent cuts
may be at dlfferent depth~, angles, and/or dlrectlons. As a
result, dlfferent portlons of the cuttlng lnsert contact the
workplece and the removed chips dlffer ln character. For
dlfferent cuts, lt ls deslrable to alter the dlrectlon of the
hlgh velocity coolant stream to provlde optlmal flow across
the lnsert and agalnst the chlp. In the described deslgn, the
dlrectlon of the coolant stream may only be altered by
changlng caps, each cap outlet havlng a partlc~lar angle of
lncllnatlon to the cuttlng lnsert.
Therefore, there ls a need for convenlently and
efflciently ad~usting the dlrectlon of the hlgh veloclty
coolant stream from a coolant supply system forming an
lntegral part of a toolholder.
8UMMARY AND OBJECTS OF THE INVENTION
The present lnventlon ls a toolholder wlth an
ad~ustable fluld chlp-breaklng means. The toolholder
comprlses a support bar formed wlth an insert seat for
recelvlng a cuttlng lnsert. The lnsert lncludes a cuttlng
edge for engaglng a workplece and removlng a chlp of metal
from the workplece. The fluld chlp-breaklng means dlrects a
stream of hlgh veloclty fluld at the chlp belng removed from
the workplece to break the chlp lnto small segments. The
chlp-breaklng means lncludes an oriflce cap mounted on top of
the support bar. The orlflce cap has a dlscharge orlflce. A
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fluid inlet means may be provlded for dellvering chlp-breaklng
fluld to the oriflce cap. Because dlfferent portlons of the
cuttlng lnsert may sometlmes be used to perform dlfferent
metal cuttlng operations, the toolholder of the present
lnventlon includes means for ad~ustlng the directlon of the
fluld stream. More partlcularly, the ad~usting means includes
a plvot member about whlch the orlflce cap rotates, and means
for rotatlng the orlflce cap about the plvot member, the means
for rotatlng belng ln a spaced relatlon to the plvot member
axls.
According to another aspect, the lnventlon may be
summarlzed as a toolholder comprlsings a) a support bar having
an insert seat for recelving a cuttlng insert, said insert
lncludlng a cuttlng edge for engaglng a workplece and removing
a chlp therefrom; b) an orlfice cap mounted on the support bar
and including a flnal passage terminating in a discharge
orlfice for dlrecting a high velocity, fluid stream at the
chip being removed from the workpiece to break the chlp into
small segments; c) means for securing the orlfice cap to the
support bar, whereln the means for securing the orlfice cap
comprises a cap screw wlth an axls therethrough, said cap
screw extends through an opening in the orlflce cap, and
whereln the support bar includes a cap screw hole for
threadably engaging the cap screwS d) an inlet passage
extending through the support bar and connected to a fluid
source; e) transfer means for transferrlng fluld from the
lnlet passage to the final passage of the orifice cap; and f)
means for rotatlng the orlflce cap to ad~ust the dlrectlon of
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the fluid stream exitlng the dlscharge orlflce, sald means for
rotatlng belng ln spaced relatlon to sald cap screw axls.
Based on the foregoing, lt ls a prlmary ob~ect of
the present lnventlon to provide a toolholder havlng a fluld
chlp-breaklng system for dlrectlng a stream of hlgh veloclty
fluld at a chlp removed from the workpiece to break the chlp
lnto small segments.
Another ob~ect of the present lnventlon ls to
provlde a toolholder of the type descrlbed above, whereln
means are provlded for ad~ustlng the dlrectlon of the chlp-
breaking fluld stream.
Another ob~ect of the present lnventlon ls to
provlde a fluld, chlp-breaklng toolholder uslng a slngle
orlfice cap which can be easily and qulckly ad~usted without
changlng orlfice caps.
Other ob~ects and advantages of the present
lnventlon wlll become apparent and obvlous from a study of the
followlng descrlptlon and the accompanylng drawlngs whlch are
merely lllustratlve of such lnventlon.
BRIEF D~S~K1~1 lON OF THE DRAWINGS
Flgure 1 ls a perspectlve vlew of the toolholder of
the present lnventlon.
Flgure 2 ls a partlal plan vlew of the toolholder.
Flgure 3 ls a sectlonal vlew of the toolholder taken through
llne III-III of Flgure 2.
Flgure 4 ls an exploded perspectlve vlew of the
toolholder.
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B
2109414
.
DETATT~n DE~ llON OF THE INVENTION
Referring now to the drawlngs, and particularly to
Flgure 1, the chlp-breaklng toolholder of the present
lnventlon ls shown thereln and lndlcated generally by the
numeral 10. The toolholder 10 includes a support bar 12
havlng a shank portion 14 and
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1067
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a head portion 16. The head portion 16 of the
toolholder 10 includes an insert seat 18 in which a
cutting insert 20 is received. The cutting insert 20
is secured in the insert seat 18 by a lock pin 24. The
cutting insert 20 includes a cutting edge 22 for
engaging a workpiece and removing a chip of metal from
the workpiece.
The toolholder includes a fluid chip-
breaking system for breaking the chip removed from the
workpiece into small segments. The fluid chip-breaking
system includes an orifice cap 30 for directing a high
velocity stream at the chip being removed from the
workpiece, and a fluid inlet means for delivering chip-
breaking fluid to the orifice cap 30. The orifice cap
30 is mounted on top of the head portion 16 of the
support bar 12 and is held by a cap screw 44. An
opening 32 (See Fig. 4) is formed in the orifice cap 30
through which an intermediate portion of the cap screw
44 extends. The opening 32 includes an upper portion
36 and a lower portion 34. The lower portion 34 of
opening 32 is smaller than the upper portion 36. A
conical surface 38 is formed between the upper and
lower portions 36 and 34. A discharge passage 40
extends from the lower p~rtion 34 of opening 32 to a
forwardly directed surface of the orifice cap where it
terminates in a discharge orifice 42.
The cap screw 44 includes a screw head 46,
and a shank which comprises an intermediate portion 48
and a threaded end portion 50. The end portion 50
threadably engages with a cap screw hole 72 formed in
the head portion 16 of the support bar 12. The cap
screw hole 72 includes a counterbore 74 surrounding the
cap screw hole 72 which defines a shoulder 76. An
o-ring seal 78 is disposed in the counterbore 74. When
the cap screw 44 is tightened, the o-ring seal 78 is
compressed between the orifice cap 30 and the
shoulder 76 to prevent fluid from escaping from
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underneath the orifice cap 30. A second o-ring seal 80
is disposed in an annular groove 52 between the head 46
of the cap screw 44 and annular ring 54. The seal 80
is compressed against the conical surface 38 to prevent
fluid from escaping through the gap between the screw
head 46 and the orifice cap 30.
The fluid inlet means for delivering chip-
breaking fluid to the orifice cap 30 includes an inlet
passage 70 which extends through the shank portion 14
of the support bar 12 into the head portion 16. The
inlet passage 70 intersects the cap screw hole 72.
Chip-breaking fluid passes from the inlet passage 70
through an access hole 58 formed in the cap screw 44.
The access hole 58 extends from the end portion 50 of
the cap screw 44 into the intermediate portion 48. A
radial opening 60 passes diametrically through the
intermediate portion 48 of the cap screw and intersects
the access hole 58. An annular channel 56 is defined
between the intermediate portion 48 of the cap screw
and the inner surface of the opening 32. The annular
channel 56 aligns with the discharge passage 40 in the
orifice cap 30. Chip-breaking fluid exits the cap
screw 44 through the radial hole 60, flows around the
shank in the annular channel 56 defined between the
intermediate portion of the shank and the inner surface
of the opening 32. The fluid enters the discharge
passage 40 in the orifice cap 30. In flowing from the
access hole 58 through the discharge passage 40, the
chip-breaking fluid accelerates and exits the discharge
orifice 42 as a high velocity, fluid stream. The
discharge orifice 42 directs the fluid stream just
above the cutting edge of the insert 20 to break the
chip being removed by the insert 20 into small
segments.
An adjustment means is provided for adjusting
the direction of the fluid stream exiting the orifice
cap 30. Such ad~ustments may be necessary when making
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different cuts with the same tool. The adjustment
means comprises a cam pin hole 82 formed in the orifice
~- cap 30 in spaced relation to the axis of the cap screw
44. A cam pin 84 cooperates with the inner surface of
the cam pin hole 82 to rotate the orifice cap 30 about
the axis of the cap screw 44, which functions as a
pivot member. More particularly, the cam pin 84
includes a shank portion 86 threadably engaged with a
cam screw hole 88 formed in the head portion 16 of the
support bar 12. The cam pin 84 includes an eccentric
head 90 which is received in the cam pin hole 82 of the
orifice cap 30. The eccentric head 90 of the cam pin
84 acts as a cam, while the inner surface of the cam
pin hole 82 acts as a cam follower. Thus, when the cam
pin 84 is rotated, it exerts a mechanical force on the
orifice cap 30 causing the orifice cap 30 to rotate
about the cap screw 44. To prevent the cam pin 84 from
binding, the cam pin hole 82 must be elongated slightly
along a line extending through the center of opening 32
to provide room for the cam pin 84 to move back and
forth.
A locking means is provided for locking the
cam pin 84 in a fixed position. In particular, a set
screw hole 92 is formed in the head portion 16 of the
toolholder 12 which intersects the cam screw hole 88.
A set screw 96 forces a plug 94 made of brass or nylon
against the shank 86 of the cam pin 84 to prevent the
cam pin 84 from inadvertently rotating out of position.
This would allow the orifice cap 30 to be replaced
without having to readjust the new orifice cap 30.
To use the toolholder of the present
invention, the cap screw 44 is slightly loosened to
permit the orifice cap 30 to rotate about the cap screw
44. After loosening the cap screw 44, the cam pin 84
is turned to adjust the direction of the fluid chip-
breaking stream. When properly adjusted, the cap screw
44 is retightened to secure the orifice cap 30 in the
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adjusted position. The toolholder is then used in a
conventional manner to perform metal working
operations.
From the forgoing, it is apparent that the
present invention provides a fluid, chip-breaking
toolholder in which the direction of the fluid stream
can be easily and quickly adjusted. The toolholder of
the present invention therefore eliminates the need for
changing orifice caps to perform different metal
working operations. Accordingly, significant savings
in costs may be realized.
The present invention may, of course, be
carried out in other specific ways than those herein
set forth without parting from the spirit and essential
characteristics of the invention. The present
embodiments are, therefore, to be considered in all
respects as illustrative and not restrictive, and all
changes coming within the meaning and equivalency range
of the appended Claims are intended to be embraced
therein.
